Tires: tire inflation, cold water line, tire inflation

Question
Which argument is correct.    When going on a trip--putting on some miles--"Since heat increases pressure one shouldn't add more air than normal in the tires before the trip"  OR  the other advice {a Cadillac owner says he was told}"Add 3-4 lb of extra air before going on the trip"

This sounds a little like the argument "What freezes first during a deep freeze?  The hot water line or the cold water line?  It would require a first class experiment to prove to me that hot water line freezes first.  The tire argument might be a little tougher to prove.

Answer
Ed,

Heat is the tire killer.

Heat generation in a tire is caused by:

1)  Deflection - load and / or pressure

2)  The amount of times deflection takes place - in other words speed.

Needless to say, the longer you drive, the less cooling time there is.

So in preparation for a trip, where speed, and time at speed, are factors, reducing the amount of deflection (adding pressure) will help reduce heat buildup, and that reduces the risk of the tire failing.